Still distraught over her breakup with Clark, Lana experiments with a dangerous serum that allows her to flatline and see her deceased parents again. A worried Clark rushes to save Lana from hurting herself but ends up being injected with the kryptonite-laced serum by an arrogant medical student. When Clark flatlines, he is able to talk to his dead father, who warns him that Lionel knows his secret. Meanwhile, Lionel continues to get closer to Martha.

Season 5 | Episode 17

Allison Mack

Chloe Sullivan

Annette O'Toole

Martha Kent

Erica Durance

Lois Lane

John Schneider

Jonathan Kent

Kristin Kreuk

Lana Lang

Michael Rosenbaum

Lex Luthor

Tom Welling

Clark Kent